The Claim:
Another video claims that repeated mRNA booster shots let the vaccine’s code reach the heart, make spike protein that scars heart tissue, disrupts its rhythm, and could cause sudden death.
The Facts:
The claims are based on articles that tried to present a new way to view the biodistribution of nanoparticles in cells, or how tiny particles move around and spread inside cells, where they go, how much of them reach different parts of the cell, and how long they stay there. The researchers tested different amounts of nanoparticles in mice, using various ways to give them, but the results might not apply to humans because mice and people have different body systems, including those that metabolize (process) substances and fight illnesses.
The study found that, no matter how the nanoparticles are administered, tagged pieces of mRNA were found in immune cells, the liver (which helps filter waste from the body), and the lungs if given through the nose. Almost none, if any, was found in the brain or heart. The mRNA levels were much lower when smaller doses, like those used in vaccines, were tested.
This doesn’t change the fact that almost all large studies and real-world data show that mRNA vaccines are safe and effective, with serious side effects, like heart inflammation, being rare and usually mild.